1. Field of the Invention
The present invention relates to an induction heating coil device, and more particularly to a high frequency induction heating coil device for generating high frequency wave or high frequency magnetic field or magnetic force and for evenly or uniformly heating objects or workpieces.
2. Description of the Prior Art
Various kinds of typical induction heating coil devices have been developed and comprise one or more high frequency induction coils provided for generating high frequency waves or high frequency magnetic field or magnetic force and for heating various objects, such as industrial die or mold devices, ovens, rice cookers, or other workpieces.
For example, U.S. Pat. No. 2,182,820 to Pisarev, discloses one of the typical induction heating coil devices including an induction coil having its end portions arranged in inwardly converging or offset relation in contrast to the conventional cylindrical type of coils.
However, the induction coil that is disposed within a susceptor or object or workpiece is disposed or arranged to have the planes of the coil turns substantially perpendicular to the susceptor, such that the flux or the magnetic field generated externally of the coil will be substantially parallel to the susceptor, and such that the susceptor or object or workpiece may not be suitably or evenly or uniformly heated.
U.S. Pat. No. 2,604,419 to Herbenar discloses another typical method for heat-treating surface hardened article and comprises a conventional cylindrical type induction coil disposed within an inner hardened layer or surface of a cylinder liner, or disposed or positioned exteriorly of an outer layer or surface of the cylinder liner.
However, the cylindrical induction coil is also disposed or arranged to have the planes of the coil turns substantially perpendicular to the cylinder liner or object or workpiece, such that the flux or the magnetic field generated externally of the induction coil will also be substantially parallel to the cylinder liner, and such that the cylinder liner may not be suitably or evenly or uniformly heated by the induction coil.
U.S. Pat. No. 6,555,801 to LeMieux et al. discloses a further typical induction heating coil device also including a conventional cylindrical or solenoid type induction coil disposed exteriorly of or around a workpiece, and at least one pancake-type induction heating coil positioned within a portion of the cylindrical or solenoid type induction coil.
However, similarly, the cylindrical induction coil and the pancake-type induction heating coil are also disposed or arranged to have the planes of the coil turns substantially perpendicular to the workpiece, such that the flux or the magnetic field generated externally of the induction coil will also be substantially parallel to the workpiece, and such that the workpiece may not be suitably or evenly or uniformly heated by the induction coil.
U.S. Patent Publication No. US-2004/0004071 A to Ogasawara et al. discloses a still further typical induction heating coil device also including a conventional cylindrical or solenoid type induction coil disposed within a workpiece or a heating roller.
However, similarly, the cylindrical induction coil is also disposed or arranged to have the planes of the coil turns substantially perpendicular to the heating roller, such that the flux or the magnetic field generated externally of the induction coil will also be substantially parallel to the heating roller, and such that the heating roller may not be suitably or evenly or uniformly heated by the induction coil.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional induction heating coil devices.